CN110838912A - Key management method, device, equipment and computer medium based on block chain - Google Patents

Abstract

The invention relates to the technical field of financial technology (Fintech), and the invention discloses a blockchain-based key management method. The method includes: when a key escrow request is received, obtaining a key corresponding to the key escrow request. key, and the escrow information of the key; generate the mnemonic corresponding to the key according to the preset mnemonic generation algorithm; process the mnemonic according to the key escrow information to obtain the mnemonic and send the sub-secret to the blockchain node corresponding to the key escrow information; when receiving the key acquisition request, send the acquisition request to the blockchain node, and receive the The block chain node is based on the sub-secret fed back by the acquisition request; the mnemonic is recovered according to the sub-secret, and the key is recovered based on the mnemonic. The invention also discloses a block chain-based key management device, equipment and computer medium. The present invention realizes effective management of keys.

Description

Blockchain-based key management method, device, device and computer medium

technical field

The present invention relates to the technical field of financial technology (Fintech), and in particular, to a blockchain-based key management method, device, equipment and computer medium.

Background technique

With the development of computer technology, more and more technologies are applied in the financial field, and the traditional financial industry is gradually transforming into financial technology (Fintech). requirements.

When sending a transaction in a blockchain network, in order to protect the transaction information of the transaction participants, it is necessary to change the sender's account address every time. Random key management can randomly generate a large number of public and private key pairs. Each time a transaction is sent, a new private key is signed and sent, and each private key needs to be saved by the user. Losing the private key will result in the loss of the corresponding account ownership and usage rights. In actual use, it is difficult for users to manage a large number of private keys. However, the loss of the private key will lead to the loss of the corresponding account ownership and use rights. Therefore, the current private key is replaced with a mnemonic for management, so that users do not need to manage a large number of private keys, but only need to save an unchanged mnemonic. But at the same time, a new problem is introduced, that is, if the mnemonic is lost, the ownership and usage rights of all the private keys derived from the mnemonic will be lost.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to propose a blockchain-based key management method, device, equipment and computer medium, aiming to solve the technical problem that the key is lost and difficult to recover in the current blockchain field.

In order to achieve the above object, the present invention provides a blockchain-based key management method, the blockchain-based key management method includes the following steps:

When receiving a key escrow request, obtain a key corresponding to the key escrow request and escrow information of the key;

Generate the mnemonic corresponding to the key according to the preset mnemonic generation algorithm;

Process the mnemonic according to the key escrow information, obtain a sub-secret corresponding to the mnemonic, and send the sub-secret to the blockchain node corresponding to the key escrow information;

When receiving a key acquisition request, send an acquisition request to the blockchain node, and receive a sub-secret fed back by the blockchain node based on the acquisition request;

The mnemonic is recovered from the sub-secret, and the key is recovered based on the mnemonic.

In one embodiment, the step of generating a mnemonic corresponding to the key according to a preset mnemonic generation algorithm includes:

Generate the entropy of the random sequence according to the preset mnemonic generation algorithm, perform hash calculation on the entropy to obtain an entropy hash value, and obtain the first m bits of the entropy hash value as a checksum, where m is greater than or equal to 1;

The checksum is added to the end of the entropy to obtain a sequence number, and the sequence number is divided to obtain a numbering unit;

Corresponding the numbering unit with a preset dictionary to obtain an ordered character string, and using the character string as a mnemonic.

In an embodiment, the mnemonic is processed according to the key escrow information to obtain a sub-secret corresponding to the mnemonic, and the sub-secret is sent to the corresponding mnemonic of the key escrow information. The steps of a blockchain node, including:

Extract the number of nodes n and the threshold value t in the key escrow information, where the number of nodes n is greater than or equal to the threshold value t, and the threshold value t refers to the value used to restore the mnemonic. The number of necessary blockchain nodes;

Encode the mnemonic to form a numerical master secret s, select the threshold t-1 coefficients, and use the coefficients to construct a t-1 order polynomial, wherein the coefficients are a1, a2 until at- 1. The polynomial is f(x)=s+a1*x+a2*x2+at-1*xt-1;

Taking the independent variable and dependent variable in the polynomial as a sub-secret, sending the sub-secret to the blockchain node corresponding to the number of nodes n, and destroying the polynomial.

In one embodiment, the step of sending the sub-secret to the blockchain node corresponding to the number of nodes n and destroying the polynomial includes:

Determine the blockchain node corresponding to the number of nodes n, and the topic name concerned by the blockchain node;

The blockchain node is connected according to the on-chain messenger protocol of the blockchain, the sub-secret corresponding to the topic name is sent to the blockchain node through the topic name channel, and the polynomial is destroyed.

In one embodiment, the step of sending an acquisition request to the blockchain node when receiving a key acquisition request, and receiving the sub-secret fed back by the blockchain node based on the acquisition request, includes:

When receiving the key acquisition request, select the threshold value t target blockchain nodes from the node number n blockchain nodes;

Send an acquisition request to the target blockchain node, and acquire the sub-secret fed back by the target blockchain node based on the acquisition request through the threshold t on-chain messenger channels.

In one embodiment, the step of recovering the mnemonic according to the sub-secret includes:

The polynomial is reconstructed by the threshold t sub-secrets, wherein the sub-secrets are the independent variable i and the dependent variable f(i), and the reconstructed polynomial is:

The numerical master secret s=f(0) is obtained by calculating the reconstructed polynomial, and the numerical master secret s is converted into a mnemonic.

In one embodiment, the step of recovering the key based on the mnemonic includes:

Divide the mnemonic into a message and a string, and iterate the string by calling a function to generate a string seed;

Separating the string seed into a master private key and a chain code corresponding to the master private key, wherein the chain code is used to generate a sub-private key according to the master private key;

A sub-private key is derived according to a preset private key derivation algorithm, and the sub-private key is used as the key corresponding to the acquisition request.

In addition, in order to achieve the above object, the present invention also provides a kind of key management device based on blockchain, and the key management device based on blockchain includes:

a first receiving module, configured to obtain a key corresponding to the key escrow request and escrow information of the key when receiving a key escrow request;

a mnemonic generation module, configured to generate a mnemonic corresponding to the key according to a preset mnemonic generation algorithm;

A processing and sending module, configured to process the mnemonic according to the key escrow information, obtain a sub-secret corresponding to the mnemonic, and send the sub-secret to the block corresponding to the key escrow information chain node;

A second receiving module, configured to send an acquisition request to the blockchain node when receiving a key acquisition request, and receive a sub-secret fed back by the blockchain node based on the acquisition request;

A key recovery module, configured to recover the mnemonic according to the sub-secret, and recover the key based on the mnemonic.

In addition, in order to achieve the above object, the present invention also provides a blockchain-based key management device, the blockchain-based key management device includes: a memory, a processor, and a device stored on the memory and available in The blockchain-based key management program running on the processor, when the blockchain-based key management program is executed by the processor, implements the above-mentioned blockchain-based key management method. step.

In addition, in order to achieve the above object, the present invention also provides a computer-readable storage medium, on which is stored a blockchain-based key management program, the blockchain-based key management program The steps when executed by the processor implement the blockchain-based key management method described above.

The present invention provides a blockchain-based key management method, device, device and computer medium. In the embodiment of the present invention, when a key escrow request is received, the key corresponding to the key escrow request and the escrow information of the key are obtained; and the key corresponding to the key is generated according to a preset mnemonic generation algorithm. mnemonic; process the mnemonic according to the key escrow information, obtain the sub-secret corresponding to the mnemonic, and send the sub-secret to the blockchain node corresponding to the key escrow information ; When receiving a key acquisition request, send an acquisition request to the blockchain node, and receive a sub-secret fed back by the blockchain node based on the acquisition request; recover the mnemonic according to the sub-secret , recover the key based on the mnemonic. In this embodiment, the key management device converts the key into a mnemonic, and processes the mnemonic to generate a sub-secret, and the key management device distributes the sub-secret based on the on-chain messenger protocol of the blockchain, and supports a retrieval mechanism at the same time; The key management device can obtain the sub-secret and use the sub-secret recovery mnemonic to restore the key from the escrow blockchain node, which realizes effective, safe, reliable and convenient escrow key escrow, and avoids permanent loss of accounts.

Description of drawings

1 is a schematic diagram of a device structure of a hardware operating environment involved in an embodiment of the present invention;

2 is a schematic flowchart of the first embodiment of the blockchain-based key management method of the present invention;

FIG. 3 is a schematic diagram of functional modules of an embodiment of a blockchain-based key management device of the present invention.

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

As shown in FIG. 1 , FIG. 1 is a schematic diagram of a device structure of a hardware operating environment involved in an embodiment of the present invention.

The blockchain-based key management device in this embodiment of the present invention may be a PC or a server.

As shown in FIG. 1 , the blockchain-based key management device may include: a processor 1001 , such as a CPU, a network interface 1004 , a user interface 1003 , a memory 1005 , and a communication bus 1002 . Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface and a wireless interface. Optionally, the network interface 1004 may include a standard wired interface and a wireless interface (eg, a WI-FI interface). The memory 1005 may be high-speed RAM memory, or may be non-volatile memory, such as disk memory. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001 .

Those skilled in the art can understand that the device structure shown in FIG. 1 does not constitute a limitation on the device, and may include more or less components than the one shown, or combine some components, or arrange different components.

As shown in FIG. 1 , the memory 1005 as a computer storage medium may include an operating system, a network communication module, a user interface module, and a blockchain-based key management program.

In the device shown in FIG. 1 , the network interface 1004 is mainly used to connect to the background server and perform data communication with the background server; the user interface 1003 is mainly used to connect to the client (client) and perform data communication with the client; and the processor 1001 can be used to call the blockchain-based key management program stored in the memory 1005, and perform the operations in the following blockchain-based key management method, the blockchain-based key management program running on the processor. For the method implemented when the key management program is executed, reference may be made to the various embodiments of the blockchain-based key management method of the present invention, which will not be repeated here.

At present, random key management schemes and deterministic hierarchical key management schemes are usually used. The random key management scheme refers to a key generation method controlled by a random algorithm. This type of key generation method is currently the most common one. Class key generation method, it generates keys according to a predetermined random algorithm or random number table, but due to the characteristics of the algorithm itself, the keys generated by any algorithm can be predicted. Deterministic hierarchical key management can start with a mnemonic, the mnemonic generates a seed, the seed generates a master private key, and the sub-private key is derived from the master private key, and the sub-private key can continue to derive sub-private keys and send transactions You can choose a new sub-private key to sign. The mnemonic remains unchanged, the user needs to save the mnemonic, but does not need to save the master private key and its sub-private keys, which solves the shortcomings of random key management. Users do not need to manage a large number of private keys, but only need to save one constant mnemonic. But at the same time, a new problem is introduced, that is, if the mnemonic is lost, all the private keys derived from the mnemonic will be lost, and the ownership and use rights of the account corresponding to the private key will be lost. The loss of key management will be greater than that of random key management.

The scheme of the embodiment of the present invention is an improvement on the deterministic hierarchical key management scheme. The present invention relates to a blockchain-based key management method, and designs a method that supports mnemonic words in deterministic hierarchical key management. The security retrieval mechanism can effectively protect the user's mnemonic phrase through the threshold encryption and decryption technology, thereby protecting the private key, thereby effectively preventing the user from permanently losing the account.

Based on the above hardware structure, an embodiment of the blockchain-based key management method of the present invention is proposed.

Referring to FIG. 2, FIG. 2 is a schematic flowchart of the first embodiment of the blockchain-based key management method of the present invention. The blockchain-based key management method includes:

Step S10, when a key escrow request is received, obtain a key corresponding to the key escrow request and escrow information of the key.

The blockchain-based key management method in this embodiment is applied to a blockchain-based key management device, the key management device receives a key escrow request, and the triggering method of the key escrow request is not specifically limited, that is, the key The escrow request can be actively triggered by the user. For example, on the display interface of the business node (also called the trading terminal), the user selects the key that needs to be escrowed and clicks the "Manage" button to actively trigger the key escrow request, and the trading terminal will encrypt the key. The key escrow request is sent to the key management device; in addition, the key escrow request can also be automatically triggered by the key management device. The key management device automatically triggers a key escrow request when a transaction generates a new key.

When the key management device receives the key escrow request, the key management device obtains the key in the key escrow request and the escrow information of the key. Wherein, the custody information includes the identity of the blockchain node to be hosted, the number of blockchain nodes n and the minimum number of blockchain nodes t (also called the threshold value t, which can be understood as the number of blockchain nodes that need to recover the key) n is greater than or equal to the number of nodes t).

Step S20, generating a mnemonic corresponding to the key according to a preset mnemonic generating algorithm.

The mnemonic generation algorithm is preset in the key management device. The preset mnemonic generation algorithm refers to a preset random algorithm for generating mnemonic words. The key management device generates a set of mnemonic words according to the preset mnemonic generation algorithm. English words, Chinese characters or characters in other languages are used as mnemonics. The number of characters in the mnemonic in this embodiment is not specifically limited. For example, the mnemonic contains 12 characters. It can be understood that the mnemonic contains 12 characters. The word is a very important parameter, and the user needs to properly save the mnemonic word for the recovery key, thereby recovering the relevant trading account.

A specific implementation of mnemonic generation is provided in this embodiment, including:

In step a1, the entropy of the random sequence is generated according to the preset mnemonic generation algorithm, the entropy is hashed to obtain an entropy hash value, and the first m bits of the entropy hash value are obtained as a checksum, wherein the said m is greater than or equal to 1;

Step a2, adding the checksum to the end of the entropy to obtain a sequence number, and dividing the sequence number to obtain a numbering unit;

Step a3: Corresponding the numbering unit with a preset dictionary to obtain an ordered character string, and using the character string as a mnemonic.

That is, in this embodiment, the key management device generates the entropy of the random sequence according to the preset mnemonic generation algorithm, the key management device performs hash calculation on the entropy to obtain the entropy hash value, and the key management device obtains the entropy hash value. The first m bits are used as the checksum, wherein the m can be determined according to the entropy length, for example, m=entropy length/32, in addition, it can be understood that m is greater than or equal to 1; the key management device adds the checksum to the The sequence number is obtained at the end of the entropy, and the sequence number is divided to obtain the numbering unit; the key management device corresponds the numbering unit with the preset dictionary (the preset dictionary refers to the dictionary preset in the key management device) to obtain sequential characters string, and use the string as a mnemonic.

For example, ① the key management device generates a random sequence (entropy) with a length of 128-256 bits (bits) according to the preset mnemonic generation algorithm; ② the key management device takes the first m bits after the entropy hash as a check sum (m=entropy length/32), a checksum of a random sequence can be created; ③ the key management device adds the checksum to the end of the random sequence (entropy); ④ the key management device adds the checksum to the sequence every 11 The bits are divided into multiple parts; ⑤The key management device maps each value containing 11 bits to a dictionary with 2048 English words, Chinese characters or other language characters that have been pre-defined; ⑥The key management device generates a Sequential English words, Chinese characters or other language strings are mnemonics. Example: A randomly generated mnemonic string is: ivory behave giggle clerk grocery firm host railchronic off lunar silent.

In this embodiment, the key management device converts the key into a mnemonic, which is convenient for users to memorize. Of course, even if the key is converted into a mnemonic, the forgetting of the mnemonic cannot be avoided. The mnemonic is managed to facilitate the recovery of the mnemonic after forgetting the mnemonic, specifically:

Step S30: Process the mnemonic according to the key escrow information to obtain a sub-secret corresponding to the mnemonic, and send the sub-secret to the blockchain node corresponding to the key escrow information.

The key management device processes the mnemonic according to the key escrow information, that is, the key escrow information includes the identity of the escrow blockchain node and the number of blockchain nodes, and the key management device processes the mnemonic to generate the number of blockchain nodes A sub-secret, the key management device distributes the sub-secret to the blockchain node corresponding to the blockchain node identifier through the on-chain protocol.

It can be understood that the key management device processes the mnemonic according to the key escrow information, and obtains the specific implementation manner of the sub-secret corresponding to the mnemonic, which is not limited. Divide the character string to obtain the character string, and the key management device encrypts the divided character string to obtain a mnemonic phrase; implementation mode 2: the key management device converts the mnemonic phrase into a numerical value, and the key management device constructs a polynomial according to the numerical value, and use the constructed polynomial as a sub-secret.

In this embodiment, the mnemonic phrase is generated by a preset mnemonic phrase generation algorithm, and the key is managed by managing the mnemonic phrase, so that the user maintains the ownership of the account corresponding to the key, and when the user forgets the mnemonic phrase, Mnemonics can be recovered, specifically:

Step S40, when receiving a key acquisition request, send an acquisition request to the blockchain node, and receive a sub-secret fed back by the blockchain node based on the acquisition request.

When the key management device receives the key acquisition request, the key management device sends the acquisition request to the blockchain node, and the blockchain node receives the acquisition request, and sends the sub-secret and the key through the designated channel according to the on-chain messenger protocol. The management device obtains the sub-secret from the on-chain messenger channel.

Step S50, recovering the mnemonic according to the sub-secret, and recovering the key based on the mnemonic.

The key management device recovers the mnemonic according to the sub-secret, that is, the key management device reversely processes the sub-secret to generate the mnemonic, for example, the mnemonic to the sub-password is partition encryption, and the sub-secret to the mnemonic is decryption. Splicing, the key management device recovers the key based on the mnemonic, specifically, including:

Step b1, the mnemonic is divided into a message and a string, and the string is iterated by calling a function to generate a string seed;

Step b2, separating the string seed into a master private key and a chain code corresponding to the master private key, wherein the chain code is used to generate a sub-private key according to the master private key;

Step b3: Derive a sub-private key according to a preset private key derivation algorithm, and use the sub-private key as the key corresponding to the acquisition request.

That is, the key management device divides the mnemonic into a message and a string, and iterates the string by calling a function to generate a string seed; the key management device separates the string seed into the master private key, and the chain corresponding to the master private key The chain code is used to generate the sub-private key according to the master private key; the private key derivation algorithm preset by the key management device refers to the preset algorithm for generating.

The key management device derives the sub-private key according to the preset private key derivation algorithm, and uses the sub-private key as the key corresponding to the acquisition request.

In this embodiment, the key management device converts the key into a mnemonic, and processes the mnemonic to generate a sub-secret, and the key management device distributes the sub-secret based on the on-chain messenger protocol of the blockchain, and supports a retrieval mechanism at the same time; The key management device can obtain the sub-secret and use the sub-secret recovery mnemonic to restore the key from the escrow blockchain node, which realizes effective, safe, reliable and convenient escrow key escrow, and avoids permanent loss of accounts.

Further, based on the first embodiment of the blockchain-based key management method of the present invention, a second embodiment of the blockchain-based key management method of the present invention is proposed.

The difference between this embodiment and the first embodiment is that in this embodiment, all blockchain nodes that have received the sub-secret do not need to restore the sub-secret, and the key can also be recovered, specifically:

First, in this embodiment, step S30 in the first embodiment is refined, including:

Extract the number of nodes n and the threshold value t in the key escrow information, where the number of nodes n is greater than or equal to the threshold value t, and the threshold value t refers to the value used to restore the mnemonic. Required number of blockchain nodes.

Encode the mnemonic to form a numerical master secret s, select the threshold t-1 coefficients, and use the coefficients to construct a t-1 order polynomial, wherein the coefficients are a1, a2 until at- 1. The polynomial is f(x)=s+a1*x+a2*x2+at-1*xt-1.

Taking the independent variable and dependent variable in the polynomial as a sub-secret, sending the sub-secret to the blockchain node corresponding to the number of nodes n, and destroying the polynomial.

That is, the key management device extracts the number of nodes n and the threshold value t in the key escrow information, and performs the threshold encryption mnemonic. The specific process is as follows:

1. The key management device selects the number of blockchain nodes n and the threshold value t, that is, at least t of the n blockchain nodes provide sub-secrets before the mnemonic can be recovered. Among them, t blockchain nodes can be controlled by key management equipment or other consortium chain participants;

2. The key management device encodes the mnemonic into a numerical master secret s, and then selects t-1 coefficients a1, a2, ... at-1, and constructs a t-1 order polynomial as: f(x)=s+ a1*x+a2*x2+at-1*xt-1.

The key management device selects n blockchain nodes, and the blockchain node identifiers are P1, P2, ..., Pn respectively. The key management device takes the independent variable and dependent variable in the polynomial as a sub-secret, and the key management device is based on The blockchain communication protocol sends the sub-secret to the blockchain node corresponding to the number of nodes n, and destroys the polynomial. For example, the sub-secret assigned by Pi is (i, f(i)), where 1<=i1< i2<...<=n. The n sub-secrets are similar to sub-private keys, which are properly kept by the blockchain nodes, and then the key management device destroys the polynomial.

The specific process of distributing sub-secrets based on the blockchain is as follows:

1. The key management device uses the on-chain messenger protocol of the blockchain to distribute sub-secrets. The key management device is connected to a blockchain node through the blockchain toolkit (SDK), and other blockchain SDKs are connected to other blockchains respectively. node.

2. The key management device determines the name of the topic concerned by the respective blockchain SDKs. For example, the topic name corresponding to the sub-secret (i, f(i)) is share_i. Then other blockchain SDKs will open the server side of the on-chain messenger protocol of their respective blockchains, and the server side will pay attention to their respective determined topics. Finally, the key management device opens the on-chain messenger protocol client through the blockchain SDK, and sends the sub-secret (i, f(i)) through the channel with the specified topic name ahare_i, and other blockchain nodes listen through the SDK. The topic channel receives the sub-secret sent by the key management device. Each channel shares the blockchain network, but is isolated from each other, so each blockchain node has a different sub-secret, which is then stored locally. At this point, the blockchain-based on-chain messenger protocol distributor is secretly completed.

For example, 1. The key management device encodes the mnemonic to form a numerical master secret s of 100, and the selection threshold is (n, t)=(4, 3), that is, n is 4 and t is 3. Therefore, the numerical master secret s needs to be divided into 4 sub-secrets, and at least 3 sub-secrets are required for recovery. A t-1-order polynomial can be constructed, that is, 3-1=2-order polynomial. If the polynomial coefficients are 5 and 3, the polynomial is: f(x)=100+5*x+3*x2. Therefore, the four sub-secrets can be selected as: (1,f(1))=(1,108), (2,f(2))=(2,122), (3,f(3))=(3,142) and ( 4,f(4))=(4,168); 2. The key management device selects 4 nodes in the blockchain for sub-secret storage, and the blockchain SDK connecting the 4 nodes pays attention to the topics share_1, share_2, share_3 and share_4, and both enable the on-chain messenger protocol server. The key management device opens the on-chain messenger protocol client through the blockchain SDK, and sends (1,108), (2,122), (3,142) and (4,168) to the topics share_1, share_2, share_3 and share_4 respectively, and the on-chain messenger protocol service The terminal receives the corresponding sub-secret and saves it locally, and destroys the polynomial.

Next, in this embodiment, step S40 in the first embodiment is refined:

When a key acquisition request is received, the threshold t target blockchain nodes are selected from the number of n blockchain nodes.

Send an acquisition request to the target blockchain node, and acquire the sub-secret fed back by the target blockchain node based on the acquisition request through the threshold t on-chain messenger channels.

That is, to request a sub-secret and restore the mnemonic, if the key management device loses the stored mnemonic, it can request to obtain t sub-secrets through at least t blockchain nodes among the n blockchain nodes. The specific process of requesting a sub-secret based on the blockchain is as follows:

1) The key management device opens the on-chain messenger protocol server through the blockchain SDK, and pays attention to t topics, the topic name is share_i, and other blockchain SDKs open the on-chain messenger protocol client, respectively to the topic named share_i The channel sends the sub-secret (i,f(i)).

2) The key management device obtains t sub-secrets from t on-chain messenger channels through the blockchain SDK.

Again, this embodiment refines step S50 in the first embodiment, including:

The polynomial is reconstructed by the threshold t sub-secrets, wherein the sub-secrets are the independent variable i and the dependent variable f(i), and the reconstructed polynomial is:

The numerical master secret s=f(0) is obtained by calculating the reconstructed polynomial, and the numerical master secret s is converted into a mnemonic.

Specifically, in the mnemonic recovery process, t sub-secrets (i, f(i)) are obtained through t nodes in the blockchain, and the polynomial can be reconstructed:

Then the numerical master secret ss=f(0) is calculated. Finally, it is converted into a mnemonic through s. This not only provides a recovery mechanism for the mnemonic of the key management device, but also prevents a single node from directly obtaining the mnemonic of the key management device, preventing malicious nodes. It also provides a flexible fault tolerance mechanism, that is, the key management device can choose the number of blockchain nodes. If n is larger, the fault tolerance will be higher, but the resource overhead will be higher.

For example, ① the key management device selects 3 nodes from 4 nodes to request to obtain sub-secrets, such as selecting blockchain nodes 1, 2 and 3. The key management device connects to a node through the blockchain SDK, opens the on-chain messenger protocol server, and pays attention to the channels with topic names share_1, share_2 and share_3. The three blockchain SDKs connected to blockchain nodes 1, 2, and 3 open the on-chain messenger protocol client, and send (1,108), (2,122), and (3,142) to the channels with topic names share_1, share_2, and share_3, respectively. Then the key management device will obtain the three sub-secrets through the blockchain.

②Through three sub-secrets, reconstruct the polynomial as follows:

Then the recovered master secret s:

Mnemonic Generation Seeds: Key management devices choose to password protect their mnemonics. If the password does not exist, an empty string is used instead. To create a seed by a mnemonic, you can use the mnemonic as the message m and the string "mnemonic" + passphrase (passphrase) as the salt to call the PBKDF2 function, iterate n times (such as 2048 times), and use HMAC-SHA512 to derive klen (=512) bit string seed seed. That is, seed=PBKDF2(HMAC-SHA512, m, salt, n, klen), wherein HMAC-SHA512 receives messages m and salt, and iteratively calculates n times to generate a klen bit string seed.

The seed generates the master private key: the seed is 512 bits, which are separated into 256 bits on the left and right, respectively recorded as IL and IR. Wherein the master private key M=IL, the chain code corresponding to the master private key C=IR, wherein the chain code is a blinding factor used to generate the sub-private key.

The master private key is derived from the sub-private key: the master private key is recorded as Kpar, the main chain code is Cpar, and the first derivation starts from the master private key, that is, Kpar=M, Cpar=C. Let i be the serial number of the sub-private key, and the private key derivation algorithm is as follows:

①I=HMAC-SHA512 (Key=Cpar, Data=Kpar||i), I is a 512-bit sequence.

②The separation I is 256 bits on the left and right, respectively denoted as IL and IR, then the sub-private key Ki=IL+Kpar, and the sub-chain code Ci=IR.

③The cycle ①② can continue to derive the child private key from the child private key. When the key management device sends a transaction, one of the sub-private keys can be selected to sign the transaction each time, and the account address of the sender of the transaction corresponds to the public key generated by the private key. Since each private key is different and the corresponding public key is different, the account address corresponding to the public key will also be different, so as to protect the privacy of user transactions.

In this embodiment, a threshold encryption technology is introduced on the basis of making full use of the deterministic hierarchical key management scheme, so that the key management device is easy to use a large number of private keys, and at the same time, the custody mode of the mnemonic is provided. Provides a core mechanism for recovering the mnemonic when the user loses the mnemonic. The key escrow scheme based on threshold encryption is more secure and stable.

Referring to FIG. 3 , an embodiment of the present invention further provides a blockchain-based key management device, where the blockchain-based key management device includes:

The first receiving module 10 is configured to, when receiving a key escrow request, obtain a key corresponding to the key escrow request, and escrow information of the key;

The mnemonic generation module 20 is used to generate the mnemonic corresponding to the key according to the preset mnemonic generation algorithm;

The processing and sending module 30 is configured to process the mnemonic according to the key escrow information, obtain a sub-secret corresponding to the mnemonic, and send the sub-secret to the area corresponding to the key escrow information blockchain node;

The second receiving module 40 is configured to send an acquisition request to the blockchain node when receiving the key acquisition request, and receive the sub-secret fed back by the blockchain node based on the acquisition request;

The key recovery module 50 is configured to recover the mnemonic according to the sub-secret, and recover the key based on the mnemonic.

In one embodiment, the mnemonic generation module 20 includes:

A hash calculation unit, configured to generate the entropy of a random sequence according to a preset mnemonic generation algorithm, perform hash calculation on the entropy to obtain an entropy hash value, and obtain the first m bits of the entropy hash value as a checksum , wherein the m is greater than or equal to 1;

A number acquisition unit, for adding the checksum to the end of the entropy to obtain a sequence number, and dividing the sequence number to obtain a number unit;

The mnemonic generating unit is used for corresponding the numbering unit and the preset dictionary to obtain an ordered character string, and using the character string as the mnemonic.

In one embodiment, the processing and sending module 30 includes:

An information extraction submodule, configured to extract the number of nodes n and the threshold value t in the key escrow information, where the number of nodes n is greater than or equal to the threshold value t, and the threshold value t refers to The number of necessary blockchain nodes for recovering the mnemonic;

A polynomial construction submodule, configured to encode the mnemonic to form a numerical master secret s, select the threshold value t-1 coefficients, and use the coefficients to construct a t-1 order polynomial, wherein the coefficients For a1, a2 up to at-1, the polynomial is f(x)=s+a1*x+a2*x2+at-1*xt-1;

The sending and destroying sub-module is used for taking the independent variable and the dependent variable in the polynomial as a sub-secret, sending the sub-secret to the blockchain node corresponding to the number of nodes n, and destroying the polynomial.

In one embodiment, the sending and destroying submodule includes:

A node determination unit, configured to determine the blockchain node corresponding to the number of nodes n, and the topic name concerned by the blockchain node;

The sending and destroying module is used to connect the blockchain node according to the on-chain messenger protocol of the blockchain, send the sub-secret corresponding to the topic name to the blockchain node through the topic name channel, and destroy it the polynomial.

In one embodiment, the second receiving module includes:

a node selection unit, configured to select the threshold value t target blockchain nodes from the node number n blockchain nodes when receiving the key acquisition request;

A sub-password acquisition unit, configured to send an acquisition request to the target blockchain node, and acquire the sub-secret fed back by the target blockchain node based on the acquisition request through the threshold t on-chain messenger channels.

In one embodiment, the key recovery module includes:

A polynomial construction unit, configured to reconstruct a polynomial through the threshold t sub-secrets, wherein the sub-secrets are an independent variable i and a dependent variable f(i), and the reconstructed polynomial is:

A mnemonic generating unit, configured to obtain the numerical master secret s=f(0) through the reconstructed polynomial calculation, and convert the numerical master secret s into a mnemonic.

In one embodiment, the key recovery module includes:

a mnemonic generating unit, for dividing the mnemonic into a message and a string, and iterating the string by calling a function to generate a string seed;

a string separation unit, configured to separate the string seed into a master private key and a chain code corresponding to the master private key, wherein the chain code is used to generate a sub-private key according to the master private key;

A key generation unit, configured to derive a sub-private key according to a preset private key derivation algorithm, and use the sub-private key as the key corresponding to the acquisition request.

For the methods executed by the above program modules, reference may be made to the various embodiments of the blockchain-based key management method of the present invention, which will not be repeated here.

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or system comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or system. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article or system that includes the element.

The above-mentioned serial numbers of the embodiments of the present invention are only for description, and do not represent the advantages or disadvantages of the embodiments.

From the description of the above embodiments, those skilled in the art can clearly understand that the method of the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is better implementation. Based on this understanding, the technical solutions of the present invention can be embodied in the form of software products in essence or the parts that make contributions to the prior art. The computer software products are stored in a storage medium (such as ROM/RAM) as described above. , magnetic disk, optical disk), including several instructions to make a server device (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in the various embodiments of the present invention.

The above are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields , are similarly included in the scope of patent protection of the present invention.

Claims (10)

1. a blockchain-based key management method, characterized in that the blockchain-based key management method comprises the steps: When receiving a key escrow request, obtain a key corresponding to the key escrow request and escrow information of the key; Generate the mnemonic corresponding to the key according to the preset mnemonic generation algorithm; Process the mnemonic according to the key escrow information, obtain a sub-secret corresponding to the mnemonic, and send the sub-secret to the blockchain node corresponding to the key escrow information; When receiving a key acquisition request, send an acquisition request to the blockchain node, and receive a sub-secret fed back by the blockchain node based on the acquisition request; The mnemonic is recovered from the sub-secret, and the key is recovered based on the mnemonic. 2. The blockchain-based key management method according to claim 1, wherein the step of generating the mnemonic corresponding to the key according to a preset mnemonic generation algorithm comprises: Generate the entropy of the random sequence according to the preset mnemonic generation algorithm, perform hash calculation on the entropy to obtain an entropy hash value, and obtain the first m bits of the entropy hash value as a checksum, where m is greater than or equal to 1; The checksum is added to the end of the entropy to obtain a sequence number, and the sequence number is divided to obtain a numbering unit; Corresponding the numbering unit with a preset dictionary to obtain an ordered character string, and using the character string as a mnemonic. 3. The blockchain-based key management method according to claim 1, wherein the mnemonic is processed according to the key escrow information to obtain a sub-secret corresponding to the mnemonic , and the step of sending the sub-secret to the blockchain node corresponding to the key escrow information includes: Extract the number of nodes n and the threshold value t in the key escrow information, where the number of nodes n is greater than or equal to the threshold value t, and the threshold value t refers to the value used to restore the mnemonic. The number of necessary blockchain nodes; Encode the mnemonic to form a numerical master secret s, select the threshold t-1 coefficients, and use the coefficients to construct a t-1 order polynomial, wherein the coefficients are a1, a2 until at- 1. The polynomial is f(x)=s+a1*x+a2*x2+at-1*xt-1; Taking the independent variable and dependent variable in the polynomial as a sub-secret, sending the sub-secret to the blockchain node corresponding to the number of nodes n, and destroying the polynomial. 4. The blockchain-based key management method according to claim 3, wherein the sub-secret is sent to the blockchain node corresponding to the number of nodes n, and the polynomial is destroyed. steps, including: Determine the blockchain node corresponding to the number of nodes n, and the topic name concerned by the blockchain node; The blockchain node is connected according to the on-chain messenger protocol of the blockchain, the sub-secret corresponding to the topic name is sent to the blockchain node through the topic name channel, and the polynomial is destroyed. 5. The blockchain-based key management method according to claim 3, wherein when a key acquisition request is received, an acquisition request is sent to the blockchain node, and the block is received. The steps of the block chain node obtaining the sub-secret that is fed back by the request include: When receiving the key acquisition request, select the threshold value t target blockchain nodes from the node number n blockchain nodes; Send an acquisition request to the target blockchain node, and acquire the sub-secret fed back by the target blockchain node based on the acquisition request through the threshold t on-chain messenger channels. 6. The blockchain-based key management method according to claim 3, wherein the step of recovering the mnemonic according to the sub-secret comprises: The polynomial is reconstructed by the threshold t sub-secrets, wherein the sub-secrets are the independent variable i and the dependent variable f(i), and the reconstructed polynomial is:

The numerical master secret s=f(0) is obtained by calculating the reconstructed polynomial, and the numerical master secret s is converted into a mnemonic. 7. The blockchain-based key management method according to any one of claims 1 to 6, wherein the step of recovering the key based on the mnemonic comprises: Divide the mnemonic into a message and a string, and iterate the string by calling a function to generate a string seed; Separating the string seed into a master private key and a chain code corresponding to the master private key, wherein the chain code is used to generate a sub-private key according to the master private key; A sub-private key is derived according to a preset private key derivation algorithm, and the sub-private key is used as the key corresponding to the acquisition request. 8. A blockchain-based key management device, wherein the blockchain-based key management device comprises: a first receiving module, configured to obtain a key corresponding to the key escrow request and escrow information of the key when receiving a key escrow request; a mnemonic generation module, configured to generate a mnemonic corresponding to the key according to a preset mnemonic generation algorithm; A processing and sending module, configured to process the mnemonic according to the key escrow information, obtain a sub-secret corresponding to the mnemonic, and send the sub-secret to the block corresponding to the key escrow information chain node; A second receiving module, configured to send an acquisition request to the blockchain node when receiving a key acquisition request, and receive a sub-secret fed back by the blockchain node based on the acquisition request; A key recovery module, configured to recover the mnemonic according to the sub-secret, and recover the key based on the mnemonic. 9. A blockchain-based key management device, characterized in that the blockchain-based key management device comprises: a memory, a processor, and a device stored on the memory and available on the processor A running blockchain-based key management program that, when executed by the processor, implements the blockchain-based encryption of any one of claims 1 to 7 The steps of the key management method. 10. A computer-readable storage medium, wherein a blockchain-based key management program is stored on the computer-readable storage medium, and when the blockchain-based key management program is executed by a processor Steps for implementing a blockchain-based key management method as claimed in any one of claims 1 to 7.

Images